Most modern automotive fuel systems use fuel injectors to deliver fuel to the engine cylinders for combustion. The fuel injectors are mounted on a fuel rail to which fuel is supplied by a pump. The pressure at which the fuel is supplied to the fuel rail must be metered to ensure the proper operation of the fuel injector. Metering is carried out using pressure regulators which control the pressure of the fuel in the system at all engine r.p.m. levels.
Pressure regulators known in the art use a valve biasing member biased to a valve seat with a longitudinal flow passage. At low fuel pressures, the valve seat is biased to a closed position to prevent the flow of fuel through the pressure regulator. As fuel pressure builds in the system, the pressure against the valve seat overcomes the biasing force of the valve biasing member, allowing fuel to flow through the valve seat, thereby controlling the fuel pressure in the system.
While such pressure regulators have been proven satisfactory, they require a substantial number of parts. In an ongoing effort to reduce the material and manufacturing costs of fuel pressure regulators, there exists a need to develop a fuel pressure regulator that is small in size with fewer parts. There also exits a need to develop a valve assembly that prevents wear of the valve seat due to erratic movement of the upper valve member.
Thus, it is believed that there is a need to provide a pressure regulator to overcome the disadvantages of the known pressure regulator.